Minimum granularity with Cron is minute while it is in days with Anacron.

Cron job can be scheduled by any normal user while Anacron can be scheduled only by the super user.

Cron expects the system to be up and running while the Anacron doesn’t expect the system to be up and running all the time.
In case of Anacron, if a job is scheduled and the system is down that time, it will execute the job as soon as the system is up and running.

Cron is ideal for servers while Anacron is ideal for desktops and laptops.

Cron should be used when you want a job to be executed at a particular hour and minute while Anacron should be used in when the job can be executed irrespective of the hour and minute.